Almost FBO and I sucked at the 1/4 mile... need advice... have logs too

[grunyon]

Hey guys.

I am a 2008 135i with 53k miles. I am running a G5 JB4, BMS WW meth kit, vrsf downpipes, and dual cone intake. For meth I was using standard -20 ww fluid. For fuel I was using 93 octane with a bottle of NOS octane boost which was probably bring me to 95 or 96 octane. For tires I have Michelin pilot super sports... 245 in the front and 265 in the back on some ARC-8's. I was running tune 3 with an additive of 50 which I figured I could handle considering the added octane. I did not bother to try to use my 2 step or no lift shift. This was all done in NJ at Raceway Park which is 55 feet above sea level and it was a dry and 45 degree night.

It was my first time to the track and I made a few rookie mistakes. Besides being nervous my first two runs and messing random stuff up, I went with a full tank of gas and I had 38 PSI in my tires.

In my third run where I generally didn't fuck anything up, I ran a 12.9 @ 111 with a 2.1 60' time.

Attached are some logs. I am looking for any advice... whether it's with my logs and my car or how I should drive it down the track. One thing mentioned to me is that I shouldn't shift at 7k. Another was that maybe I should launch in second?

Any advice appreciated. Thank you!

p.s. Why is a .csv an invalid file?

[Chris.]

38 psi is too much. Shoot for low 20s

[fly_inverted]

Do you have an aftermarket FMIC ?

shift at 6K...
launch in 1st
and like anything....practice practice practice

[b1aze]

Even with a bad driver, it should run faster than that, no??

[Davyhay]

You'd pick up several tenths by shifting at 5800.

[grunyon]

No intercooler. I was under the impression that such an upgrade dropped to the bottom of my list once I had meth injection.

shifting at 5800 huh? low 20 PSI on pilot super sports? Are you sure?

Also, I spent a little bit looking at my logs and figuring things out. I had meth flow issues that I did not notice when I was in the car doing the run. I've never had meth flow issues before so this must be a fluke. Will do more testing and reseating of meth lines today.

Also, I have a strange throttle lift thing going on that Terry and I have been noticing on my logs for a while now... just looking at the graph I thought I had a mid RPM timing drop forever. But when I looked at the .csv I noticed that even though I was at 100% pedal my throttle would drop from 100% to like 72% then 46% then back up to 100%... and this all happened at the same time as my "timing drop".

Terry has been telling me forever to turn my traction control off but I swear it is off... I hold the DTC button for like 5 seconds until the triangle/circle/exclamation thing displays. Any ideas what this could be?

[Davyhay]

Originally Posted by grunyon

shifting at 5800 huh?

On my car, stock, I picked up 3/10 of a second by shifting at 5800ish as opposed to redline.

[brusk]

I seem to be asking this alot lately but have you had your valves cleaned? I noticed that made a noticeable difference on mine and I've only got 28K miles on it. Your 60' times aren't horrible not sure what your prep is but I found at the track I used to go to was to skip the water or just drive through it depending on your track and spin the tires over just a few times on the way to the line, I would do this about 3 times until the tires were clean and I could feel them gribbing a little more.

As for you shifting point it varries on each car best thing to do is take a dyno graph and use an online shift point calculator and plug in your numbers. The shift point will vary from gear to gear getting lower and lower. On paper 1st is good for about 6300 dropping about 200RPM's each gear and 5800 being the lowest RPM. Having said that if your having traction problems in 1st some people just get off the line in 1st and grab 2nd real early.

[lowbudgethero]

I feel like the octane booster is doing more harm than good too, imo.

The throttle drop could be your issue though, do you feel it while you're driving?

60' time could be better too for the mods you have

[Vigilante375]

Shifting......like it was mentioned, look at your dyno graph and see where your peak HP is. If it's at 6k, then shift at 6k. Why shift at 6.5k if you're losing hp? Just because the engine can turn 6.5k doesn't mean you NEED to shift there. 5.8k is generally the point to shift.

Tire pressure.....your 60' is on average for our cars for the average person. 2.0-2.2 is the range since the IRS in these cars cause some bad wheel hop and you have to manipulate the clutch or throttle just right to keep it under control. I believe most people have the boost turned down in first then when they shift to the next gears it's maxed out. So on non drag radial tires somewhere in the 22-24 range should be the ideal spot for rear tires. For your fronts you could put the max air pressure in them if you want since they don't do anything other than steer the car and maxing the PSI out would let you have least rolling resistance.

1/2 tank of fuel or less plus doing a quick burnout for the 1st 2 runs would be ideal. I find that doing a quick burnout on the first 2 runs will help the tires to hook up after that. More importantly, practice makes perfect. What RPMs did you launch at? I like around 2500-2800 with a side step and rolling into first then WOT after that. But I believe the best way is to manipulate the clutch while launching......

[brusk]

Originally Posted by Vigilante375

Shifting......like it was mentioned, look at your dyno graph and see where your peak HP is. If it's at 6k, then shift at 6k. Why shift at 6.5k if you're losing hp? Just because the engine can turn 6.5k doesn't mean you NEED to shift there. 5.8k is generally the point to shift.

Your not factoring in gearing, in 1st gear (assuming your not spinning) you can actually make more power higher up compared to how the torque will be multiplied in the next gear. Again with most dyno sheets I've seen on stock turbo's it's still only a few hundred RPM's. Only way to tell though is to grab a good current dyno graph and punch it in to a shift calculator that factors in the gear ratios, final drive and tire size.

[BadOneThreeFive]

Your 60 foot is terrible. I highly suggest getting some drag radials. I use Mickey Thompson's and I get 1.7s on my 60 foot. For every tenth of a second you knock off the 60 foot, you will cross the finish 2 tenths faster. Also, your FBO w/ meth, so your boost should be higher. I was hitting 19 and tapering to 17 and if im not mistaken you can lower the boost in 1st and 2nd gear with the JB4 (I never tried it). I would play with that to get your 60 foot down.

[Spoolin Montego]

Learn to launch better, and don't shift at 7k. I usually shift at 6k